Centralized system for the remote monitoring of multimedia signals

ABSTRACT

A centralized system for the monitoring of remote multimedia signals which monitors and assesses the quality of the services distributed over an IP packet telecommunications network ( 30 ) comprising a plurality of customer premises equipment ( 22 - 2 ), one of the items of such equipment being connectable to an access gateway ( 21 ), such as a digital subscriber line access multiplexer (DSLAM), via a line ( 23 ) susceptible of receiving multimedia content such as data, voice and video over IP; the said content being returned direct to the access multiplexer via a return line ( 24 ).

SUBJECT OF THE INVENTION

The present invention refers, in general, to a centralized system formonitoring and assessing the quality of telecommunications services and,more specifically, to a device hereby to assess and monitor the qualityof the services offered over packet telecommunications networks, such asthe distribution of television via Internet protocol based networks(IPTV).

STATE OF THE ART

In recent years access networks have been laid out fundamentally withxDSL (digital subscriber loop) technologies which permit theexploitation of the copper based subscriber loop infrastructure.

Up to now the xDSL access technologies have covered the technical,management and capacity requirements imposed by the services which themarket has demanded.

However, users are increasingly calling for more multimedia servicesbased principally on quality video and voice over Internet, in additionto the existing Internet access services, known collectively as “tripleplay”, and operators are thus having to progressively increase thecapacity of their access networks.

The aforementioned circumstances has allowed operators to offer a broadrange of services of all kinds Via applications based on Internetprotocols, such as IPTV and the streaming of multimedia content, voiceand data over IP.

In order to provide multimedia services in real time on IP networks itis necessary to comply with a series of requirements which depend on theservice or the combination of services offered. For example, a givenbandwidth, which may be different in each transmission direction, isneeded so that the incoming packets line may allow the multimediasignals to be regenerated correctly. The operator must also guaranteethat the quality of encoding is satisfactory and that delays, networklatency and the percentage of lost packets are not in excess of givenlimits depending on the type of service.

As a consequence of the foregoing, the provider of IPTV and otherreal-time services needs to control the quality of the service (QoS)given to the end user and is therefore obliged to install, throughoutthe Internet, the metropolitan network or the access network, quality ofservice monitoring equipment.

In order to assess the quality of that service, reference is made tosuch parameters as the delay of the packets of data transmitted, thebandwidth used in the communication, the packet delay jitter or the lossprobability of packets, or others of a similar nature which may permitthe appraisal of the quality of the service of the stream of televisiondata transmitted from the content provider to the subscribers as awhole. In the case of IPTV, multimedia signals are also superviseddirect via TV monitor observation. A perception of the service similarto that of the end user may thus be achieved.

The monitoring signals and the aforementioned assessment data aregathered at different points distributed throughout thetelecommunications network.

It is known in the state of the art, shown in FIG. 1, that a digitalsubscriber line access multiplexer 21 represents one of the possiblepoints of monitoring. It is to these items of equipment, which aregenerally located in telephone exchanges, that the lines of the endusers are connected. The connection is made via customer premisesequipment 22. An example of customer premises equipment 22-1 is an ADSLrouter to which the end user may connect a range of items such asmultimedia decoders or set-top boxes 27-1, computers PC or IPtelephones. FIG. 1 represents an example in which customer premisesequipment 22-1, set-top boxes 27-1, computer PC and an IP telephone makeup the home equipment of an end subscriber.

The digital subscriber line access multiplexer 21 such as DSLAM may havea plurality of subscriber ports. In order to monitor the multimedia ordata signals received by the digital subscriber line access multiplexer21 it is common practice to reserve one of those ports for the purpose.

It is known in the art that in order to obtain the parameters requiredfor the monitoring and assessment of service quality in a digitalsubscriber line access multiplexer 21 the procedure is to connect to thesubscriber port reserved for that purpose, in cascade and via amonitoring line 23 as shown in FIG. 1, a customer premises equipment22-2, a multimedia decoding device or set-top box 27-2 and a computer11. These items of equipment are installed beside the digital subscriberline access multiplexer 21.

The computer 11 is in turn connected, likewise in cascade, to the DSLAM21 or to some other item of telecommunications network access equipmentvia a return line 24. The computer 11 receives the signal generated bythe set-top boxes 27-2, for example, an analogue television signal,processes it and transmits it via the return line 24 to a central server29 by means of a communications channel laid down through thetelecommunications network 30. The computer 11 similarly gathers andtransmits to the central server 29 the signal service qualityparameters.

At the central server 29 the monitoring and assessment of the multimediasignal received by every DSLAM 21 from the provider of content and/orservices is performed by means of direct observation and thecorresponding algorithms based on the parameters registered in eachcase.

The known system of monitoring and assessment has a number ofdisadvantages. The interconnection of various pieces of equipment andmiddleware is required to obtain the return signal for monitoring andthe quality of service assessment parameters. Further, the multimediasignal received by the central server 29 is not the digital signalreceived by the DSLAM 21 but, instead, a signal processed by the set-topbox 27-2 and the computer 11 connected to the monitoring line 24 asshown in FIG. 1.

As a result, the assessment of the television signal received by theDSLAM 21 is performed in an indirect manner and calls for the use of acomplex system including various items of equipment. The overall cost ofthe quality of service assessment system is therefore high, while themonitored signal is not that received by the DSLAM 21.

CHARACTERISTICS OF THE INVENTION

The present invention seeks to resolve or to minimize one or more of thedisadvantages mentioned above by means of a centralized system formonitoring remote multimedia signals as described in claim 1. Theembodiments of the invention are as established in the dependent claims.

One object of the invention is that of providing a system for themonitoring and assessment of the quality of the services rendered by aprovider of content and/or services within a packet telecommunicationsnetwork which genuinely gauges the quality of the triple play services,comprising voice, data and television over IP, delivered by thatprovider to the end subscriber.

The packet network quality of service assessment data takes in both QoSparameters perceptible to the customer and those pertaining to theoperation of the network.

Another object of the invention is that of providing a simple systemrequiring a minimum amount of devices. The number of such items ofequipment is consequently reduced.

A further object of the invention is that of avoiding the increase ofrestrictions on the topology of the communications network and on theincrease in the number of access gateways such as access multiplexersDSLAMs.

A further object of the invention is that of providing a monitoring andassessment system requiring a minimum consumption of electricity for itsoperations and thus helping the parties to the Kyoto protocol to meettheir obligations thereunder.

A further object of the invention is that of providing an Internet QoSmonitoring and assessment system at an affordable overall cost for theInternet content provider, so that the system may adapt easily to marketneeds at any time and that there may be scalability in the investment innetwork infrastructure and the assessment of Internet services.

BRIEF DESCRIPTION OF THE FIGURES

A more detailed explanation of the invention is provided in thefollowing description of the attached figures.

FIG. 1 shows a packet telecommunications network monitoring systemaccording to the state of the art, and

FIG. 2 shows an IP monitoring system according to the invention.

DESCRIPTION OF THE INVENTION

There follows a description, with reference to FIG. 2, of a system forthe monitoring of the IP multimedia services rendered by a provider ofIP content and/or services.

The assessment system includes an item of subscriber access equipment22-2 such as customer premises equipment CPE, an ADSL modem, connectedto an access gateway 21 such as a digital subscriber line accessmultiplexer DSLAM via a line reserved 23 for that purpose.

The access multiplexer 21 may be located OD the premises of theprovider's customer, which may for example be a company, although it ismore commonly located in a telephone exchange.

When the access multiplexer 21 receives from the Internet contentprovider Internet services such as triple play services it relays thestream of multimedia content, which includes IPTV, to subscriber portsconnected thereto.

One of the items of subscriber access equipment receiving that flow oftelevision over Internet is subscriber access equipment 22-2 which formspart of the monitoring system. The transmission of the IPTV stream fromthe access multiplexer 21 takes place via a monitoring line 23.

Upon receiving the IPTV stream, subscriber access equipment 22-2 returnsit to the access multiplexer DSLAM 21 from which it came via the returnline 24.

In the implementation as shown in FIG. 2, subscriber access equipment22-2 receives the multimedia stream from access multiplexer DSLAM 21 viaa downstream line 23 as an ADSL line and returns it via an Ethernet line24 in turn linking subscriber access 22 to the access multiplexer DSLAM21.

The access multiplexer 21 is in turn linked to switch such as a firstEthernet switch 25-1 and thus, via a telecommunications network 30 Whichincludes an IP network, it is connected to the monitoring server 29which is in turn linked to the network 30 through a second Ethernetswitch 25-2.

The IPTV stream returned to the access multiplexer 21 from thesubscriber access equipment 22-2 is relayed to the monitoring server 29through a communication channel 31 laid down between the first andsecond Ethernet switches 25-1, 25-2.

The communication channel 31 thus laid down across thetelecommunications network 30 conveys packets of data relating to thereturned IPTV stream obtained through the application of a tunnelingprotocol such as the virtual leased line (VLL) protocol. By means ofthis procedure the packets of multimedia flow originally received bysubscriber access equipment 22 from access multiplexer 21 may betransmitted to the monitoring server 29 without alteration.

The second Ethernet switch 25-2 is connected to at least one multimediadecoder 27-3 such as a set-top box. The number of set-top boxes 27-3connected to that second switch 25-2 will depend on the number of accessmultiplexer DSLAM 21 to be monitored simultaneously.

By means of a computer application the operator of the centralmonitoring server 29 may relay to a given set-top box 27-3 the signalcoming from a given access multiplexer 21 DSLAM. The set-top box 27-3generates a television signal which may be seen on a monitor 26.Similarly, the operator of the central monitoring server 29 may performon the set-top box 27-3 all or part of the actions that the end user maycarry out with his remote control. The operator thus obtains aperception of the service similar to that of the end user.

The tunnel 31 between both switches 25-1, 25-2 also allowscommunications to be conveyed unaltered from the set-top box 27-3controlled by the monitoring 29 server to the remote subscriber accessequipment 22 used to send the monitoring signal of the accessmultiplexer DSLAMs 21.

Upon receipt of the packets of data relating to the monitoring signalsfrom the access multiplexer DSLAMs 21, the central monitoring server 29executes an assessment algorithm using the parameters obtained from theanalysis of the packets received from each access multiplexer DSLAM 21.

The monitoring system of multimedia traffic 28 enables the remoteconnection of any subscriber access equipment 22-2 of a plurality ofitems of subscriber access equipment 22, with any set-top box 27-3 of aplurality of set-top box 27-3.

Also the monitoring system 28 permits the capture by the monitoringserver 29 of the remote return signal coming from any of the subscriberaccess equipment 22-2. Furthermore, the monitoring server 29 may beconnected to a set-top box 27-3 by means of infrared transmitterscontrolled by the monitoring server 29.

The embodiments and examples contained in this specification are putforward by way of explanation of the significance of the presentinvention and of the practical application thereof, so that experts inthe art may put into practice and use the invention. The experts in theart will appreciate, however, that the preceding description andexamples only constitute an outline. The description is not intended tobe all encompassing, nor is the scope of the invention restrictedthereto. Many modifications and variations may therefore be made withoutparting company with the spirit and scope of the following claims.

1. A system for monitoring and assessing the quality of servicesdistributed over a packet telecommunications network, such as theInternet, comprising at least one piece of subscriber access equipment(22-2) and an access gateway (21); wherein the subscriber accessequipment (22-2) is connectable to the access gateway (21) via a line(23) susceptible of receiving multimedia content such as data, voice andvideo, the said content being returned to the communications network(30) via a return line (24).
 2. System according to claim 1, wherein thereturn line (24) providing a link of predetermined capacity to returnthe multimedia stream, said return line (24) may be of a technology suchas an Ethernet line.
 3. System according to claim 2, wherein a linesusceptible of conveying the multimedia stream from the access gateway(21) to the subscriber access equipment (22-2) is connectable to asubscriber port of the access gateway (21) and therefore uses a type ofaccess technology such as xDSL or the like.
 4. System according to claim3, wherein the access equipment (22-2) is capable of communicatingthrough return line (24) with a remote multimedia traffic monitoring(29) server via a packet telecommunications network (30).
 5. Systemaccording to claim 4, wherein the packet telecommunications network (30)comprises a first interface (25-1) connectable to the access gateway(21) and a second interface (25-2) connectable to the traffic monitoring(29) server, so that the return signal is conveyed unaltered between thefirst and second interface (25-1, 25-2), and vice versa, via a tunnelcommunication protocol for packets such as a virtual leased line (VLL).6. System according to claim 5, wherein the first and second interfaces(25-1, 25-2) may be Ethernet switches, ATM switches, routers, accessmultiplexers or the like.
 7. System according to claim 5, wherein thesecond interface (25-2) is connectable to at least a multimedia decoder(27-3).
 8. System according to claim 7, wherein between the subscriberaccess equipment (22-2) and the multimedia decoder (27-3) there is adirect tunnelled communication channel (51), without there being a needfor a specific configuration of the subscriber access equipment (22-2)or of the multimedia decoder (27-3).
 9. System according to claim 1,wherein the subscriber access equipment (22-2) is a customer premisesequipment such as an ADSL modem, a residential router or the like. 10.System according to claim 1, wherein the access gateway (21) is adigital subscriber line access multiplexer, access media gateway or thelike,
 11. System according to claim 1 wherein the access gateway isconnectable to the subscriber access equipment (22-2) wherein the accessgateway (21) is connectable to a remote monitoring server.
 12. Systemaccording to claim 11, wherein the access gateway (21) is connectable tothe subscriber access equipment (22-2) via a line susceptible ofconveying a stream of multimedia content downward, from access gateway(21) to subscriber access equipment (22-2), the said stream ofmultimedia content then returning uplink via a return line (24). 13.System according to claim 12, wherein the subscriber access equipment(22-2) may establish bi-directional contact with a remote multimediadecoder (27-3).
 14. A system according to claim 6 having a multimediadecoder, wherein the multimedia decoder (27-3) is connectable to theremote quality of service monitoring server (29) via the secondinterface (25-2).
 15. A procedure for monitoring and assessing thequality of services provided over a packet telecommunications network(30), comprising the broadcasting of television over IP networks;wherein it comprises the step of direct transmission of a stream ofmultimedia content, including television over packet networks, from anaccess gateway (21) to subscriber access equipment (22-2) and returns tothe communications network (30) via a return line (24).
 16. Procedureaccording to claim 15 wherein it also comprises the step of transmissionusing a tunnel communication protocol from the access gateway (21) to aremote monitoring server (29).
 17. A procedure according to claim 16,wherein it enables the remote connection of at least one piece ofsubscriber access equipment (22-2) with any multimedia decoder (27-3) ofa plurality of multimedia decoders (27-3),
 18. A procedure according toclaim 17, wherein it permits the capture by the monitoring server (29)of a remote return signal coming from any item of the subscriber accessequipment (22-2).
 19. A procedure according to claim 18, wherein themonitoring server (29) is connectable to a multimedia decoder (27-3) bymeans of infrared transmitters controlled by the monitoring server (29).